1.Field of the Invention
Embodiments of the present invention generally relate to apparatus and methods for manufacturing magnetic media. More specifically, embodiments of the present invention relate to apparatus and methods for patterning magnetically susceptible layers on magnetic media.
2.Description of the Related Art
Magnetic media are used in various electronic devices such as hard disk drives (HDD) and magnetoresistive random access memory (MRAM) devices. Magnetic media devices store and retrieve information using magnetic domains. A hard-disk drive generally includes magnetic media in the form of disks having magnetic domains that are separately addressable by a magnetic head. The magnetic head moves into proximity with a magnetic domain and alters the magnetic properties of the magnetic domain to record information. To recover the recorded information, the magnetic head moves into proximity with the magnetic domain and detects the magnetic properties of the magnetic domain. The magnetic properties of the magnetic domain are generally interpreted as corresponding to one of two possible states, the “0” state and the “1” state. In this way, digital information may be recorded on magnetic media and recovered thereafter.
Magnetic media typically comprise a non-magnetic glass, composite glass/ceramic, or metal substrate with magnetically susceptible layers formed thereon. The magnetically susceptible layer is generally patterned such that the surfaces of the magnetic media have areas of magnetic susceptibility interspersed with areas of magnetic inactivity.
Traditionally, the magnetically susceptible layer is patterned by imprinting a photoresist layer to form a pattern over the magnetically susceptible layer and implanting the magnetically susceptible layer with the imprinted photoresist layer acting as a mask. However, there are several problems with this traditional approach. Because imprinting the photoresist layer aims to leave small pillars of photoresist to form the pattern, upon lifting off the imprint die, small pillars of the photoresist are sometime erroneously removed with the imprint die, thus, creating defects. The photoresist suitable for pattern imprinting is typically a weak polymer that may be damaged by subsequent processing conditions. Additionally, because the imprinting process limits the thickness of the photoresist, photoresist of greater thickness for withstanding subsequent processing conditions cannot be used.
Therefore, there is a need to improve the patterning process in magnetic media manufacturing.